Phosphite compounds and the metal complexes thereof

ABSTRACT

Phosphites of the formula I or II                  
 
and their metal complexes, their preparation and the use of the phosphites as ligands in catalytic reactions, in particular in processes for the hydroformylation of olefins, are described.

The present invention relates to phosphites and their metal complexes,and the preparation and the use of the phosphites as ligands incatalytic reactions.

The reactions between olefin compounds, carbon monoxide and hydrogen inthe presence of a catalyst to form the aldehydes having one more carbonatom is known as hydroformylation (oxo process). As catalysts in thesereactions, use is frequently made of compounds of the transition metalsof groups 8 to 10 of the Periodic Table of the Elements, in particularcompounds of rhodium and of cobalt. Compared to catalysis by cobaltcompounds, the hydroformylation using rhodium compounds generally offersthe advantage of higher selectivity and is thus usually more economical.In the case of the rhodium-catalyzed hydroformylation, use is usuallymade of complexes comprising rhodium and preferably trivalent phosphoruscompounds as ligands. Known ligands are, for example, compounds from theclasses of phosphines, phosphites and phosphonites. An overview ofhydroformylation of olefins may be found in B. CORNILS, W. A. HERRMANN,“Applied Homogeneous Catalysis with Organometallic Compounds”, Vol. 1&2,VCH, Weinheim, N.Y., 1996.

Each catalyst system (cobalt or rhodium) has its specific advantages.Depending on the starting material and target product, differentcatalyst systems are used. If rhodium and triphenylphosphine areemployed, α-olefins can be hydroformylated at relatively low pressures.An excess of triphenylphosphine is generally used asphosphorus-containing ligand; a high ligand/rhodium ratio is necessaryto increase the selectivity of the reaction giving the commerciallydesired n-aldehyde product.

U.S. Pat. Nos. 4,694,109 and 4,879,416 relate to bisphosphine ligandsand their use in the hydroformylation of olefins at low synthesis gaspressures. Particularly in the hydroformylation of propene, highactivities and high n/i selectivities are achieved using ligands of thistype.

WO-A-95/30680 describes bidentate phosphine ligands and their use incatalysis, including in hydroformylation reactions.

Ferrocene-bridged bisphosphines are disclosed, for example, in U.S. Pat.Nos. 4,169,861, 4,201,714 and 4,193,943 as ligands forhydroformylations.

Selent D. et al, Angewandte Chemie, International Edition, volume 40,No. 9, WILEY-VCH Verlag GmbH, Weinheim 2001, pages 1696 to 1698discloses biphosphite ligands containing a phosphorinone structural unitand their use for hydroformylation catalysts.

A disadvantage of bidentate phosphine ligands is their relativelycomplicated preparation. It is therefore often not economically viableto use such systems in industrial processes.

Rhodium-monophosphite complexes are suitable catalysts for thehydroformylation of branched olefins having internal double bonds, butthe selectivity for terminally hydroformylated compounds is low. EP-A-0155 508 discloses the use of bisarylene-substituted monophosphites inthe rhodium-catalyzed hydroformylation of sterically hindered olefins,e.g. isobutene.

Rhodium-bisphosphite complexes catalyze the hydroformylation of linearolefins having terminal and internal double bonds to give predominantlyterminally hydroformylated products, while branched olefins havinginternal double bonds are reacted to only a small extent. Onco-ordination to a transition metal center, these phosphites givecatalysts of increased activity, but the operating life of thesecatalyst systems is unsatisfactory, partly because of the hydrolysissensitivity of the phosphite ligands. The use of substituted bisaryldiols as starting materials for the phosphite ligands, as described inEP-A-0 214 622 or EP-A-0 472 071, has enabled considerable improvementsto be achieved.

According to the literature, the rhodium complexes of these ligands areextremely active hydroformylation catalysts for α-olefins. U.S. Pat.Nos. 4,668,651, 4,748,261 and 4,885,401 describe polyphosphite ligandsby means of which α-olefins and also 2-butene can be converted with highselectivity into the terminally hydroformylated products. In U.S. Pat.No. 5,312,996, bidentate ligands of this type are also used for thehydroformylation of butadiene.

Although the bisphosphites mentioned are good complexing ligands forrhodium hydroformylation catalysts, it is desirable to develop new typesof readily preparable phosphites to further improve their effectiveness,for example in hydroformylation.

It has surprisingly been found that novel phosphites of the structuralformula I or II,

where R¹, R², R³ and R⁴ are each selected independently from amongmonovalent substituted or unsubstituted aliphatic, aromatic,heteroaromatic, mixed aliphatic-alicyclic, mixed aliphatic-aromatic,heterocyclic, mixed aliphatic-heterocyclic hydrocarbon radicals havingfrom 1 to 50 carbon atoms, H, F, Cl, Br, I, —CF₃, —CH₂(CF₂)_(j)CF₃ wherej=0–9, —OR⁹, —COR⁹, —CO₂R⁹, —CO₂M, —SR⁹, —SO₂R⁹, —SOR⁹, —SO₃R⁹, —SO₃M,—SO₂NR⁹R¹⁰, —NR⁹R¹⁰, —N═CR⁹R¹⁰, where R⁹ and R¹⁰ are selectedindependently from among H, monovalent substituted or unsubstitutedaliphatic and aromatic hydrocarbon radicals having from 1 to 25 carbonatoms and M is an alkali metal ion, formally half an alkaline earthmetal ion, an ammonium ion or phosphonium ion,

-   or adjacent radicals R¹ to R⁴ together form a fused substituted or    unsubstituted aromatic, heteroaromatic, aliphatic, mixed    aromatic-aliphatic or mixed heteroaromatic-aliphatic ring system;-   Q is a k-valent substituted or unsubstituted aliphatic, alicyclic,    mixed aliphatic-alicyclic, heterocyclic, mixed    aliphatic-heterocyclic, aromatic, mixed aliphatic-aromatic    hydrocarbon radical having from 1 to 50 carbon atoms, where    aliphatic parts of Q may contain oxygen, sulfur and/or nitrogen,-   k is at least 2 and R¹, R², R³ and R⁴ in the individual structural    elements bound to Q can be different from one another, are suitable    complexing ligands. If the radicals R¹ to R⁴ in the individual    structural elements bound to Q are different from one another, the    phosphite is unsymmetrical.

The invention also provides complexes of the phosphite ligands with ametal of group 4, 5, 6, 7, 8, 9 or 10 of the Periodic Table of theElements and their preparation.

The present invention further provides for the use of the phosphites andthe phosphite-metal complexes in catalysis, preferably in homogeneouscatalysis, in particular in the hydroformylation of olefins.

Further aspects of the invention are a process for the hydroformylationof olefins and a process for preparing the phosphite ligands.

In preferred phosphites of the formula I or II, at least two adjacentradicals R¹ to R⁴ together form a fused aromatic, heteroaromatic,aliphatic, mixed aromatic-aliphatic or mixed heteroaromatic-aliphaticring system which is unsubstituted or is substituted by at least oneradical selected from among aliphatic, alicyclic, aromatic,heteroaromatic, mixed aliphatic-alicyclic, mixed aliphatic-aromatic,heterocyclic, mixed aliphatic-heterocyclic hydrocarbon radicals havingfrom 1 to 50 carbon atoms, F, Cl, Br, I, —CF₃, —CH₂(CF₂)_(j)CF₃ wherej=0–9, —OR⁹, —COR⁹, —CO₂R⁹, —CO₂M, —SR⁹, —SO₂R⁹, —SOR⁹, —SO₃R⁹, —SO₃M,—SO₂NR⁹R¹⁰, —NR⁹R¹⁰ or —N═CR⁹R¹⁰, where R⁹, R¹⁰ and M are as definedabove.

In the phosphites of the formula I or II, Q is preferably a divalent totetravalent radical. For example, Q can have a structure as shown informula III,

where R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷ and R¹⁸ are as defined for R¹ toR⁴ in claim 1 or 2, W is the divalent radical CR¹⁹R²⁰, where R¹⁹ and R²⁰are as defined for R⁹ and R¹⁰, m=0–1 and the positions a and b representthe linkage points. Adjacent radicals R¹¹ to R¹⁸ may, in a manneranalogous to R¹ to R⁴ in formula (I) or (II), together form a fusedsubstituted or unsubstituted aromatic, heteroaromatic, aliphatic, mixedaromatic-aliphatic or mixed heteroaromatic-aliphatic ring system. Thering system is preferably substituted by at least one radical selectedfrom among aliphatic, alicyclic, aromatic, heteroaromatic, mixedaliphatic-alicyclic, mixed aliphatic-aromatic, heterocyclic, mixedaliphatic-heterocyclic hydrocarbon radicals having from 1 to 50 carbonatoms, F, Cl, Br, I, —CF₃, —CH₂(CF₂)_(j)CF₃ where j=0–9, —OR⁹, —COR⁹,—CO₂R⁹, —CO₂M, —SR⁹, —SO₂R⁹, —SOR⁹, —SO₃R⁹, —SO₃M, —SO₂NR⁹R¹⁰, —NR⁹R¹⁰or —N═CR⁹R¹⁰, where R⁹, R¹⁰ and M are as defined above.

Other examples of Q are a phenyl radical, a naphthyl radical, a bisarylradical, a radical of a diphenyl ether or a calix[n]arene radical havingthe structure corresponding to the formula IV:

where R²¹, R²² and R²³ are selected independently from among substitutedor unsubstituted aliphatic and aromatic hydrocarbon radicals having from1 to 25 carbon atoms, H, F, Cl, Br, I, —CF₃, —CH₂(CF₂)_(j)CF₃ wherej=0–9, —OR²⁴, —COR²⁴, —CO₂R²⁴, —CO₂M, —SR²⁴, —SO₂R²⁴, —SOR²⁴, —SO₃R²⁴,—SO₃M, —SO₂NR²⁴R²⁵, —NR²⁴R²⁵ and —N═CR²⁴R²⁵, where R²⁴ and R²⁵ are asdefined for R⁹ and R¹⁰ and M is an alkali metal ion, formally half analkaline earth metal ion, an ammonium ion or phosphonium ion, oradjacent radicals R²¹ to R²³ together form a fused substituted orunsubstituted aromatic, heteroaromatic, aliphatic, mixedaromatic-aliphatic or mixed heteroaromatic-aliphatic ring system; Y isthe divalent radical CR²⁴R²⁵ or CR²⁴R²⁵—O—CR²⁴R²⁵; n=3–6 and thepositions a represent the linkage points or are occupied by OR²⁴, whereR²⁴ and R²⁵ are as defined above.

Representative phosphite ligands of the formula I or II are:

The examples (I) to (M) are unsymmetrical phosphites.

The phosphites for the use according to the invention can be preparedfrom phosphorus-halides by means of a sequence of reactions withalcohols, carboxylic acids and/or α-hydroxyarylcarboxylic acids in whichthe halogen atoms on the phosphorus are replaced by oxygen groups. Oneof a number of possibilities for preparing the phosphites of theinvention is the following synthetic route for bisphosphites:

In a first step, an α-hydroxyarylcarboxylic acid (1) is reacted with aphosphorus trihalide PX₃, e.g. PCl₃, PBr₃ and PI₃, preferably phosphorustrichloride PCl₃, in the presence of a base which is preferably used inequivalent or catalytic amounts to form a halodioxaphosphorinone (2).

In a second reaction step, the halodioxaphosphorinone (2) is reactedwith a diol (HO-Q-OH) or a dicarboxylic acid (HOOC-Q-COOH) in thepresence of a base which is preferably used in equivalent or catalyticamounts to give the desired phosphite (I) or (II).

The radicals R¹ to R⁴ and Q are as defined above.

In the synthesis of unsymmetrical bisphosphites, two differentlysubstituted chlorodioxaphosphorinones (2a) and (2b) in which at leastone radical R¹ to R⁴ and (2b) has a different meaning in (2a) areprepared in the first reaction step and these are then, in the secondreaction step, reacted in succession with the diol or the dicarboxylicacid in the presence of a base which is preferably used in equivalent orcatalytic amounts.

Since the diols or dicarboxylic acids used and their downstream productsare frequently solid, the reactions are generally carried out insolvents. Solvents used are aprotic solvents which react neither withthe diols nor dicarboxylic acids nor with the phosphorus compounds.Examples of suitable solvents are tetrahydrofuran, ethers, such asdiethyl ether or MTBE (methyl tert-butyl ether) and aromatichydrocarbons such as toluene.

The reaction of phosphorus-halides with alcohols forms hydrogen halidewhich is bound by added bases. Examples of bases which can be used forthis purpose are tertiary amines such as triethylamine, pyridine orN-methylpyrrolidinone. It may also be useful to convert the alcoholsinto metal alkoxides prior to the reaction, for example by reacting themwith sodium hydride or butyllithium.

The phosphites are suitable ligands for the complexation of metals ofgroups 4, 5, 6, 7, 8, 9 and 10 of the Periodic Table of the Elements.The complexes can contain one or more phosphite ligands and, if desired,further ligands and are suitable as catalysts, preferably in homogeneouscatalysis. Examples of suitable metals are rhodium, cobalt, iridium,nickel, palladium, platinum, iron, ruthenium, osmium, chromium,molybdenum and tungsten. Particularly in the case of metals of group 8,9 or 10, the resulting complexes can be used as catalysts forhydroformylation, carbonylation, hydrogenation and hydrocyanationreactions; particular preference is given to rhodium, cobalt, nickel,platinum and ruthenium. For example, the use of rhodium in particular ascatalyst metal gives high catalytic activities in hydroformylationreactions. The catalyst metals are used in the form of salts orcomplexes, in the case of rhodium, for example, rhodium carbonyls,rhodium nitrate, rhodium chloride, Rh(CO)₂(acac) (acac—acetylacetonate), rhodium acetate, rhodium octanoate or rhodium nonanoate.

The active catalyst species for the homogeneous catalysis are formedfrom the phosphite ligands of the invention and the catalyst metal underthe reaction conditions, for instance in the case of hydroformylation acarbonylhydridophosphite complex on contact with synthesis gas. Thephosphites and any further ligands can be introduced into the reactionmixture in free form together with the catalyst metal (as salt orcomplex) in order to generate the active catalyst species in situ. It isalso possible to use a phosphite-metal complex comprising the abovementioned phosphite ligands and the catalyst metal as precursor for theactual catalytically active complex. These phosphite-metal complexes areprepared by reacting the appropriate catalyst metal of groups 4 to 10 inelemental form or in the form of a chemical compound with the phosphiteligand.

As additional ligands present in the reaction mixture, it is possible touse phosphorus-containing ligands, for example phosphines, phosphites,phosphonites or phosphinites.

Examples of such ligands are:

phosphines: triphenylphosphine, tris(p-tolyl)phosphine,tris(m-tolyl)phosphine, tris(o-tolyl)phosphine, tris(p-methoxyphenyl)phosphine, tris(p-dimethylaminophenyl)phosphine,tricyclohexylphosphine, tricyclopentylphosphine, triethylphosphine,tri(1-naphthyl)phosphine, tribenzylphosphine, tri-n-butylphosphine,tri-t-butylphosphine.

Phosphites: trimethyl phosphite, triethyl phosphite, tri-n-propylphosphite, tri-i-propyl phosphite, tri-n-butyl phosphite, tri-i-butylphosphite, tri-t-butyl phosphite, tris(2-ethylhexyl)phosphite, triphenylphosphite, tris(2,4-di-t-butylphenyl)phosphite,tris(2-t-butyl-4-methoxyphenyl)phosphite,tris(2-t-butyl-4-methylphenyl)-phosphite, tris(p-cresyl)phosphite. Inaddition, sterically hindered phosphite ligands as are described, interalia, in EP-A-155,508, U.S. Pat. Nos. 4,668,651, 4,748,261, 4,769,498,4,774,361, 4,835,299, 4,885,401, 5,059,710, 5,113,022, 5,179,055,5,260,491, 5,264,616, 5,288,918, 5,360,938, EP-A-472,071, EP-A-518,241and WO-A-97/20795 are also suitable ligands.

Phosphonites: methyldiethoxyphosphine, phenyldimethoxyphosphine,phenyldiphenoxyphosphine, 2-phenoxy-2H-dibenzo[c,e] [1,2]oxaphosphorinand its derivatives in which all or some of the hydrogen atoms have beenreplaced by alkyl and/or aryl radicals or halogen atoms, and alsoligands as are described in WO-A-98/43935, JP-A-09-268152 and DE-A-19810 794 and in the German Patent Applications DE-A-199 54 721 andDE-A-199 54 510.

Useful phosphinite ligands are described, inter alia, in U.S. Pat. No.5,710,344, WO-A-95/06627, U.S. Pat. No. 5,360,938 or JP-A-07-082281.Examples are diphenyl(phenoxy)phosphine and its derivatives in which allor some of the hydrogen atoms have been replaced by alkyl and/or arylradicals or halogen atoms, diphenyl(methoxy)phosphine anddiphenyl(ethoxy)phosphine.

The phosphites or phosphite-metal complexes of the invention can be usedin processes for the hydroformylation of olefins, preferably thosehaving from 2 to 25 carbon atoms, to form the corresponding aldehydes.Here, preference is given to using phosphite complexes with metals oftransition group 8 as catalyst precursors.

In general, from 1 to 500 mol, preferably from 1 to 200 mol, morepreferably from 2 to 50 mol, of the phosphite of the invention are usedper mol of metal of transition group 8. Fresh phosphite ligand can beadded to the reaction at any point in time in order to keep theconcentration of free ligand constant.

The concentration of the metal in the reaction mixture is in the rangefrom 1 ppm to 1000 ppm, preferably in the range from 5 ppm to 300 ppm,based on the total weight of the reaction mixture.

The hydroformylation reactions carried out using the phosphites of theinvention or the corresponding metal complexes are carried out by knownmethods as described, for example, in J. FALBE, “New Syntheses withCarbon Monoxide”, Springer Verlag, Berlin, Heidelberg, N.Y., page 95ff., (1980). The olefin compound(s) is (are) reacted in the presence ofthe catalyst with a mixture of CO and H₂ (synthesis gas) to form thealdehydes having one more carbon atom.

The reaction temperatures for a hydroformylation process using thephosphites or phosphite-metal complexes of the invention as catalyst arepreferably in the range from 40° C. to 180° C., more preferably from 75°C. to 140° C. The pressures under which the hydroformylation proceedsare preferably 1–300 bar of synthesis gas, more preferably 10–64 bar.The molar ratio of hydrogen to carbon monoxide (H₂/CO) in the synthesisgas is preferably from 10/1 to 1/10, more preferably from 1/1 to 2/1.

The catalyst or the ligand is present as a homogeneous solution in thehydroformylation mixture comprising starting materials (olefins andsynthesis gas) and products (aldehydes, alcohols, high boilers formed inthe process). A solvent can be additionally used if desired.

Owing to their high molecular weight, the phosphites of the inventionhave a low volatility. They can therefore be separated off easily fromthe more volatile reaction products. They have a sufficiently goodsolubility in customary organic solvents.

The starting materials for the hydroformylation are olefins or mixturesof olefins which have from 2 to 25 carbon atoms and a terminal orinternal C═C double bond. They can be linear, branched or have a cyclicstructure and can also have a plurality of olefinically unsaturatedgroups. Examples are propene; 1-butene, cis-2-butene, trans-2-butene,isobutene, butadiene, mixtures of C₄-olefins; C₅-olefins such as1-pentene, 2-pentene, 2-methyl-1-butene, 2-methyl-2-butene,3-methyl-1-butene; C₆-olefins such as 1-hexene, 2-hexene, 3-hexene, theC₆-olefin mixture formed in the dimerization of propene (dipropene);C₇-olefins such as 1-heptene, further n-heptenes, 2-methyl-1-hexene,3-methyl-1-hexene; C₈-olefins such as 1-octene, further n-octenes,2-methylheptenes, 3-methylheptenes, 5-methyl-2-heptene,6-methyl-2-heptene, 2-ethyl-1-hexene, the isomeric C₈-olefin mixtureformed in the dimerization of butenes (dibutene); C₉-olefins such as1-nonene, further n-nonenes, 2-methyloctenes, 3-methyloctenes, theC₉-olefin mixture formed in the trimerization of propene (tripropene);C₁₀-olefins such as n-decenes, 2-ethyl-1-octene; C₁₂-olefins such asn-dodecenes, the C₁₂-olefin mixture formed in the tetramerization ofpropene or the trimizeration of butenes (tetrapropene or tributene),C₁₄-olefins such as n-tetradecenes, C₁₆-olefins such as n-hexadecenes,the C₁₆-olefin mixture formed in the tetramerization of butenes(tetrabutene) and also olefin mixtures prepared by cooligomerization ofolefins having different numbers of carbon atoms (preferably from 2 to4), if desired after separation into fractions having the same number ora similar number of carbon atoms by distillation. It is likewisepossible to use olefins or olefin mixtures produced by theFischer-Tropsch synthesis and also olefins which are obtained byoligomerization of ethene or are obtainable via methathesis reactions ortelomerization reaction.

Preferred starting materials are α-olefins in general, e.g. propene,1-butene, 2-butene, 1-hexene, 1-octene and also dimers and trimers ofbutene (dibutene, di-n-butene, diisobutene, tributene).

The hydroformylation can be carried out continuously or batchwise.Examples of industrial apparatuses are stirred vessels, bubble columns,jet nozzle reactors, tube reactors and loop reactors, some of which maybe cascaded and/or provided with internals.

The reaction can be carried out in one or more steps. The separation ofthe aldehyde compounds formed and the catalyst can be carried out by aconventional method, e.g. fractionation. Industrially, this can beachieved, for example, by means of a distillation, by means of a fallingfilm evaporator or a thin film evaporator. This is particularly usefulwhen a solution of the catalyst in a high-boiling solvent is separatedfrom the lower-boiling products. The catalyst solution which has beenseparated off can be used for further hydroformylations. When lowerolefins (e.g. propene, butene, pentene) are used, it is also possiblefor the products to be discharged from the reactor via the gas phase.

The following examples illustrate the present invention.

EXAMPLES

All examples were carried out under protective gas using standardSchlenk techniques. The solvents were dried over suitable desiccantsbefore use.

Chloro Compound A

Chloro compound A (2-chloro-4H-1,3,2-benzodioxaphosphorin-4-one) wasprocured from Aldrich, Taufkirchen, and used as supplied.

Chloro Compound B

Chloro compound B was prepared from 2-hydroxy-1-naphthalenecarboxylicacid using a method based on that in BE 667036, Farbwerke Hoechst AG,1966; Chem. Abstr. 65 (1966) 13741d. The following description explainsthe procedure for the synthesis:

Reaction of 2-hydroxy-1-naphthalenecarboxylic acid with PhosphorusTrichloride

9.22 g (0.049 mmol) of 2-hydroxy-1-naphthalenecarboxylic acid, 200 ml ofdried toluene and 0.48 g (0.005 mol) of N-methyl-2-pyrrolidinone areplaced in a 250 ml Schlenk tube. 10.14 g (0.073 mol) of phosphorustrichloride are slowly added to this mixture while stirring. After theSchlenk tube has been connected to an offgas line provided with a gasflowmeter, the reaction mixture is carefully heated to 95° C. andmaintained at this temperature for 5 hours. For the work-up, thereaction mixture is filtered and the solvent of the filtrate is removedunder reduced pressure.

Yield: 11.01 g (44.6 mmol), corresponding to 91.0% of theory.

³¹P-NMR (toluene-D₈): δ 150.9 ppm

Preparation of calix[4]arene bis(O-acyl Phosphite) 1 (Mixture ofDiastereomers)

1.85 ml of a solution of n-butyllithium (1.6 mol/l, 2.96 mmol) in hexanewas slowly added at room temperature to a solution of 1.0 g (1.48 mmol)of p-tert-butylbisdimethoxycalix[4]arene I in 40 ml of THF. Theresulting solution was stirred at RT for 2 hours. 0.75 g (2.96 mmol) of3-chloro-2,4-dioxa-3-phosphaphenanthren-1-one II dissolved in 5 ml ofTHF was subsequently added dropwise via a needle. A color change fromcolorless to yellowish occurred after the addition was complete. Thesolution was stirred overnight. Evaporation of the solvent gave crudebisphosphite 1 as a yellow solid. The product was purified bydissolution in 30 ml of CH₂Cl₂ and filtration through Celite® kieselguhrfilter aid. Evaporation of the solution at 50° C. gave 1 as a yellowishair- and moisture-sensitive solid.

Yield: 1.24 g (1.26 mmol, 85%):

m.p. 278° C.

¹H-NMR in CDCl₃ (400.1 MHz): □=0.51 (s, 18 H, C(CH ₃)₃); 0.53 (s, 18 H,C(CH ₃)₃); 0.92 (s, 18 H, C(CH ₃)₃); 0.95 (s, 18 H, C(CH ₃)₃); 3.10 (d,4 H, ²J(HH)=12.8 Hz, Ar—CH ₂—Ar); 3.11 (d, 4 H, ²J(HH)=13.0 Hz, Ar—CH₂—Ar); 3.68 (s, 6 H, O—CH ₃); 3.73 (s, 6 H, O—CH ₃); 4.26 (d, 4 H,²J(HH)=12.4 Hz, Ar—CH ₂—Ar); 4.35 (d, 4H, ²J(HH)=12.8 Hz, Ar—CH ₂—Ar);6.11 (d, 2H, ⁴J(HH)=2.4 Hz, Ar—H); 6.13 (d, 2H, ⁴J(HH)=2.3 Hz, Ar—H);6.38 (d, 2 H, ⁴J(HH)=2.3 Hz, Ar—H); 6.42 (d, 2 H, ⁴J(HH)=2.2 Hz, Ar—H);6.55 (d, 2 H, ⁴J(HH)=2.2 Hz, Ar—H; 6.62 (d, 2 H, ⁴J(HH)=2.3 Hz, Ar—H);6.63 (d, 4 H, ⁴J(HH)=2.3 Hz, Ar—H); 7.07–7.88 (m, 20 H, naph-H); 8.96(d, 2 H, ³J(HH)=8.0 Hz, naph-H); 8.99 (d, 2 H, ³J(HH)=7.9 Hz, naph-H),

¹³C-NMR in CDCl₃ (100.6 MHz): □=30.48 (s, 6 C, C(CH₃)₃); 30.66 (s, 6 C,C(CH₃)₃); 31.30 (s, 6 C, C(CH₃)₃); 31.33 (s, 6 C, C(CH₃)₃); 32.06 (s, 4C, Ar—CH₂—Ar); 32.10 (s, 4 C, Ar—CH₂—Ar); 33.82 (s, 2 C, C(CH₃)₃); 33.84(s, 2 C, C(CH₃)₃); 33.85 (s, 2 C, C(CH₃)₃); 33.87 (s, 2 C, C(CH₃)₃);61.01 (s, 2 C, O—CH₃); 61.28 (s, 2 C, O—CH₃); 118.49 (s, 4 C, naph-C);124.79–129.50 (m, 40 C, Ar—C and naph-C); 129.87–146.21 (m, 48 C, Ar—C_(quart.) and naph-C _(quart.)).

³¹P-NMR in CDCl₃ (81.0 MHz): □=102.3, 103.5, 104.1, 104.6.

EI-MS, m/z (%): 1108 (4) [M]⁺; 892 (5) [M+H−R]⁺; 675 (50) [M−2 R]⁺.

Elemental analysis:

C₆₈H₇₀O₁₀P₂ (1109.25) calc. C 73.63 H 6.36 P 5.58 found:C 70.13 H 6.37 P5.30

Hydroformylation of 1-octene using calix[4]arene bis-O-acyl phosphite) 1

The hydroformylations were carried out in a Buddeberg 200 ml autoclaveprovided with pressure maintenance valve, gas flow meter and spargingstirrer. The autoclave was charged under an argon atmosphere with 10 mlof a 0.604 mM solution of rhodium in the form of[Rh(1.5-cyclooctadiene)acac] (acac=acetyl acetonate anion) as catalystprecursor, 5 ml of toluene as GC standard and the appropriate amounts ofTHF and calix[4]arene bis(O-acylphosphite) 1. 15 ml of 1-octene wereplaced in the pressure pipette. The total volume of the reactionsolution was 56 ml. After replacement of the argon atmosphere byflushing with synthesis gas (CO/H₂ 1:1) the rhodium/ligand mixture washeated to 100 or 120° C. while stirring (1500 rpm) under a synthesis gaspressure of 30–33 bar. When the desired reaction temperature had beenreached, the synthesis gas pressure was increased to 40 or 50 bar andkept constant by means of a pressure regulator during the entirereaction time. After addition of the olefin, the gas consumption wasrecorded by means of a Hitec gas flowmeter from Bronkhorst (NL). Thereaction time for each of the hydroformylation experiments was 3 hours.The reaction mixture was subsequently cooled to room temperature, theautoclave was vented and flushed with argon. 2 ml of the autoclavesolution were admixed with 10 ml of pentane and analyzed by gaschromatography; no olefin hydrogenation or alcohol formation weredetected in the analysis.

TABLE 1 Hydroformylation of 1-octene C₉- aldehydes, Straight- Molartotal, chain C₉- ratio of of which aldehyde Branched C₉-aldehydesRh:bis- Yield n-C9 i-C8 i-C7 i-C6 n/iso phosphite [mol %] [mol %] [mol%] [mol %] [mol %] [mol %] 1:1 83.3 53.4 35.1 7.3 4.2 1.15 1:2 85.4 58.934.0 5.0 2.1 1.43  1:10 46.0 59.2 39.0 1.5 0.3 1.45 n-C9 = nonanal i-C8= 2-methyloctanal i-C7 = 2-ethylheptanal i-C6 = 2-propylhexanal n/iso =Ratio of nonanal/sum of all branched C₉-aldehydes.

1. A phosphite of the formula I,

where R¹, R², R³ and R⁴ are each independently a monovalent substitutedor unsubstituted aliphatic, alicyclic, aromatic, heteroaromatic, mixedaliphatic-alicyclic, mixed aliphatic-aromatic, heterocyclic, mixedaliphatic-heterocyclic hydrocarbon radical having from 1 to 50 carbonatoms, H, F, Cl, Br, I, —CF₃, —CH₂(CF₂)_(j)CF₃ where j=0–9, —OR⁹, —COR⁹,—CO₂R⁹, —CO₂M, —SR⁹, —SO₂R⁹, —SO₃R⁹, —SO₃M, —SO₂NR⁹R¹⁰, —NR⁹R¹⁰, or—N═CR⁹R¹⁰, where R⁹ and R¹⁰ are independently a H, monovalentsubstituted or unsubstituted aliphatic and aromatic hydrocarbon radicalhaving from 1 to 25 carbon atoms and M is an alkali metal ion, analkaline earth metal ion, an ammonium ion or a phosphonium ion, oradjacent radicals R¹ to R⁴ together form a fused substituted orunsubstituted aromatic, heteroaromatic, aliphatic, mixedaromatic-aliphatic or mixed heteroaromatic-aliphatic ring system; Q is ak-valent substituted or unsubstituted aliphatic, alicyclic, mixedaliphatic-alicyclic, aromatic, heteroaromatic, or mixedaliphatic-aromatic hydrocarbon radical having from 1 to 50 carbon atoms,where aliphatic parts of Q may contain one or more of oxygen, sulfur ornitrogen, k is at least 2 and R¹, R², R³ and R⁴ in the individualstructural elements bound to Q can be different from one another.
 2. Thephosphite as claimed in claim 1, wherein at least two adjacent radicalsR¹ to R⁴ together form a fused aromatic, heteroaromatic, aliphatic,mixed aromatic-aliphatic or mixed heteroaromatic-aliphatic ring systemwhich is unsubstituted or is substituted by at least one radicalselected from among aliphatic, alicyclic, aromatic, heteroaromatic,mixed aliphatic-alicyclic, mixed aliphatic-aromatic, heterocyclic, mixedaliphaticheterocyclic hydrocarbon radicals having from 1 to 50 carbonatoms, F, Cl, Br, I, —CF₃, —CH₂(CF₂)_(j)CF₃ where j=0–9, —OR⁹, —COR⁹,—CO₂R⁹, —CO₂M, —SR⁹, —SO₂R⁹, —SOR⁹, —SO₃R⁹, —SO₃M, —SO₂NR⁹R¹⁰, —NR⁹R¹⁰or —N═CR⁹R¹⁰.
 3. The phosphite as claimed in claim 1, wherein Q is adivalent hydrocarbon radical of the formula III

and R¹¹, R¹², R¹³, R¹⁴, R¹⁵ , R¹⁶, R¹⁷ and R¹⁸ are each independently amonovalent substituted or unsubstituted aliphatic, alicyclic, aromatic,heteroatomic, mixed aliphatic-alicyclic, mixed aliphatic-aromatic,heterocyclic, mixed aliphatic-heterocyclic hydrocarbon radical havingfrom 1 to 50 carbon atoms, H, F, Cl, Br, I, —CF₃, —CH₂(CF₂)_(j)CF₃ wherej=0–9, —OR⁹, —COR⁹, —CO₂R⁹, —CO₂M, —SR⁹, —SO₂R⁹, —SO₃R⁹, —SO₃M,—SO₂NR⁹R¹⁰, —NR⁹R¹⁰, or —N═CR⁹R¹⁰ where R⁹ and R¹⁰ are independently aH, monovalent substituted or unsubstituted aliphatic and aromatichydrocarbon radical having from 1 to 25 carbon atoms and M is an alkalimetal ion, an alkaline earth metal ion, an ammonium ion or a phosphoniumion, W is the divalent radical CR¹⁹R²⁰, where R¹⁹ and R²⁰ are as definedfor R⁹ and R¹⁰, m=0–1 and the positions a and b represent the linkagepoints.
 4. The phosphite as claimed in claim 1, wherein Q is acalix[n]arene radical of the formula IV

where R²¹, R²² and R²³ are independently a substituted or unsubstitutedaliphatic and aromatic hydrocarbon radical having from 1 to 25 carbonatoms, H, F, Cl, Br, I, —CF₃, —CH₂(CF₂)_(j)CF₃ where j=0–9, —OR²⁴,—COR²⁴, —CO₂R²⁴, —CO₂M, —SR²⁴, —SO₂R²⁴, —SOR²⁴, —SO₃R²⁴, —SO₃M,—SO₂NR²⁴R²⁵, —NR²⁴R²⁵, —N═CR²⁴R²⁵, where R²⁴ and R²⁵ are independently aH, monovalent substituted or unsubstituted aliphatic and aromatichydrocarbon radical having from 1 to 25 carbon atoms and M is an alkalimetal ion, an alkaline earth metal ion, an ammonium ion or a phosphoniumion, or adjacent radicals R²¹ to R²³ together form a fused substitutedor unsubstituted aromatic, heteroaromatic, aliphatic, mixedaromaticaliphatic or mixed heteroaromatic-aliphatic ring system; Y isthe divalent radical CR²⁴R²⁵ or CR²⁴R²⁵—O—CR²⁴R²⁵, n=3–6 and thepositions a represent the linkage points or are occupied by OR²⁴, whereR²⁴ and R²⁵ are as defined above.
 5. A phosphite-metal complexcomprising a metal of group 4, 5, 6, 7, 8, 9 or 10 of the Periodic Tableof the Elements and one or more phosphites as claimed in claim
 1. 6. Thephosphite-metal complex as claimed in claim 5, wherein the metal isrhodium, platinum, palladium, cobalt or ruthenium.
 7. A process for thehydroformylation of olefins, which comprises reacting a monoolefin ormonoolefin mixture with a mixture of carbon monoxide and hydrogen in thepresence of a phosphite-metal complex as claimed in claim
 5. 8. Aprocess for preparing a phosphite as claimed in claim 1, which comprises(a) reacting an α-hydroxyarylcarboxylic acid of the formula (1)

with PCl₃, PBr₃ or PI₃ in the presence of a base to form ahalodioxaphosphorinone of the formula (2),

where Hal=Cl, Br or I, and (b) reacting the halodioxaphosphorinone (2)in the presence of a base with (i) a diol HO-Q-OH to give a phosphite ofthe formula (I), or (ii) a dicarboxylic acid HOOC-Q-COOH to give aphosphite of the formula (II).
 9. The process for preparing a phosphiteas claimed in claim 8, wherein two differently substitutedhalodioxaphosphorinones (2a) and (2b) are synthesized in (a) and arethen reacted in succession with a diol in (b) (i) or reacted insuccession with a dicarboxylic acid in (b) (ii) to give an unsymmetricalphosphite.
 10. A process for preparing a phosphite-metal complex asclaimed in claim 5, which comprises reacting a metal of group 4, 5, 6,7, 8, 9 or 10 of the Periodic Table in elemental form or in the form ofa chemical compound with the phosphite of formula (I).
 11. A catalystcomprising the phosphite as claimed in claim
 1. 12. A homogeneouscatalyst comprising the phosphite as claimed in claim
 1. 13. Ahydroformylation catalyst comprising the phosphite as claimed inclaim
 1. 14. A hydroformylation catalyst comprising the phosphite metalcomplex as claimed in claim
 5. 15. The process as claimed in claim 7wherein the reacting is carried out in the presence of one or moreadditional phosphorous-containing ligands.
 16. A phosphite of theformula II,

where R¹, R², R³ and R⁴ are each independently a monovalent substitutedor unsubstituted aliphatic, alicyclic, aromatic, heteroatomic, mixedaliphatic-alicyclic, mixed aliphatic-aromatic, heterocyclic, mixedaliphatic-heterocyclic hydrocarbon radical having from 1 to 50 carbonatoms, H, F, Cl, Br, I, —CF₃, —CH₂(CF₂)_(j)CF₃ where j=0–9, —OR⁹, —COR⁹,—CO₂R⁹, —CO₂M, —SR⁹, —SO₂R⁹, —SO₃R⁹, —SO₃M, —SO₂NR⁹R¹⁰, —NR⁹R¹⁰, or—N═CR⁹R¹⁰, where R⁹ and R¹⁰ are independently a H, monovalentsubstituted or unsubstituted aliphatic and aromatic hydrocarbon radicalhaving from 1 to 25 carbon atoms and M is an alkali metal ion, analkaline earth metal ion, an ammonium ion or a phosphonium ion, oradjacent radicals R¹ to R⁴ together form a fused substituted orunsubstituted aromatic, heteroaromatic, aliphatic, mixedaromatic-aliphatic or mixed heteroaromatic-aliphatic ring system; Q is ak-valent substituted or unsubstituted aliphatic, alicyclic, mixedaliphatic-alicyclic, heterocyclic, aromatic, heteroaromatic, or mixedaliphatic-aromatic hydrocarbon radical having from 1 to 50 carbon atoms,where aliphatic parts of Q may contain one or more of oxygen, sulfur ornitrogen, k is at least 2 and R¹, R², R³ and R⁴ in the individualstructural elements bound to Q can be different from one another. 17.The phosphite as claimed in claim 16, wherein at least two adjacentradicals R¹ to R⁴ together form a fused aromatic, heteroaromatic,aliphatic, mixed aromatic-aliphatic or mixed heteroaromatic-aliphaticring system which is unsubstituted or is substituted by at least oneradical selected from among aliphatic, alicyclic, aromatic,heteroaromatic, mixed aliphatic-alicyclic, mixed aliphatic-aromatic,heterocyclic, mixed aliphatic heterocyclic hydrocarbon radicals havingfrom 1 to 50 carbon atoms, F, Cl, Br, I, —CF₃, —CH₂(CF₂)_(j)CF₃ wherej=0–9, —OR⁹, —COR⁹, —CO₂R⁹, —CO₂M, —SR⁹, —SO₂R⁹, —SOR⁹, —SO₃R⁹, —SO₃M,—SO₂NR⁹R¹⁰, —NR⁹R¹⁰ or —N═CR⁹R¹⁰.
 18. The phosphite as claimed in claim16, wherein Q is a divalent hydrocarbon radical of the formula III

and R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷ and R¹⁸ are each independently amonovalent substituted or unsubstituted aliphatic, alicyclic, aromatic,heteroatomic, mixed aliphatic-alicyclic, mixed aliphatic-aromatic,heterocyclic, mixed aliphatic-heterocyclic hydrocarbon radical havingfrom 1 to 50 carbon atoms, H, F, Cl, Br, I, —CF₃, —CH₂(CF₂)_(j)CF₃ wherej=0–9, —OR⁹, —COR⁹, —CO₂R⁹, —CO₂M, —SR⁹, —SO₂R⁹, —SO₃R⁹, —SO₃M,—SO₂NR⁹R¹⁰, —NR⁹R¹⁰, or —N═CR⁹R¹⁰ where R⁹ and R¹⁰ are independently aH, monovalent substituted or unsubstituted aliphatic and aromatichydrocarbon radical having from 1 to 25 carbon atoms and M is an alkalimetal ion, an alkaline earth metal ion, an ammonium ion or a phosphoniumion, W is the divalent radical CR¹⁹R²⁰, where R¹⁹ and R²⁰ are as definedfor R⁹ and R¹⁰, m=0–1 and the positions a and b represent the linkagepoints.
 19. The phosphite as claimed in claim 16, wherein Q is acalix[n]arene radical of the formula IV

where R²¹, R²² and R²³ are independently a substituted or unsubstitutedaliphatic and aromatic hydrocarbon radical having from 1 to 25 carbonatoms, H, F, Cl, Br, I, —CF₃, —CH₂(CF₂)_(j)CF₃ where j=0–9, —OR²⁴,—COR²⁴, —CO₂R²⁴, —CO₂M, —SR²⁴, —SO₂R²⁴, —SOR²⁴, —SO₃R²⁴, —SO₃M,—SO₂NR²⁴R²⁵, —NR²⁴R²⁵, —N═CR²⁴R²⁵, where R²⁴ and R²⁵ are R⁹ and R¹⁰ areindependently a H, monovalent substituted or unsubstituted aliphatic andaromatic hydrocarbon radical having from 1 to 25 carbon atoms analkaline and M is an alkali metal ion, an alkaline earth metal ion, anammonium ion or a phosphonium ion, or adjacent radicals R²¹ to R²³together form a fused substituted or unsubstituted aromatic,heteroaromatic, aliphatic, mixed aromatic aliphatic or mixedheteroaromatic-aliphatic ring system; Y is the divalent radical CR²⁴R²⁵or CR²⁴R²⁵—O—CR²⁴R²⁵, n=3–6 and the positions a represent the linkagepoints or are occupied by OR²⁴, where R²⁴ and R²⁵ are as defined above.20. A phosphite-metal complex comprising a metal of group 4, 5, 6, 7, 8,9 or 10 of the Periodic Table of the Elements and one or more phosphitesas claimed in claim
 16. 21. The phosphite-metal complex as claimed inclaim 5, wherein the metal is rhodium, platinum, palladium, cobalt orruthenium.
 22. The phosphite-metal complex as claimed in claim 20,wherein the metal is rhodium, platinum, palladium, cobalt or ruthenium.23. A process for the hydroformylation of olefins, which comprisesreacting a monoolefin or monoolefin mixture with a mixture of carbonmonoxide and hydrogen in the presence of a phosphite-metal complex asclaimed in claim
 20. 24. A process for preparing a phosphite as claimedin claim 16, which comprises (a) reacting an α-hydroxyarylcarboxylicacid of the formula (1)

with PCl₃, PBr₃ or PI₃ in the presence of a base to form ahalodioxaphosphorinone of the formula (2),

where Hal=Cl, Br or I, and (b) reacting the halodioxaphosphorinone (2)in the presence of a base with (i) a diol HO-Q-OH to give a phosphite ofthe formula (I), or (ii) a dicarboxylic acid HOOC-Q-COOH to give aphosphite of the formula (II).
 25. The process for preparing a phosphiteas claimed in claim 24, wherein two differently substitutedhalodioxaphosphorinones (2a) and (2b) are synthesized in (a) and arethen reacted in succession with a diol in (b) (i) or reacted insuccession with a dicarboxylic acid in (b) (ii) to give an unsymmetricalphosphite.
 26. A process for preparing a phosphite-metal complex asclaimed in claim 20, which comprises reacting a metal of group 4, 5, 6,7, 8, 9 or 10 of the Periodic Table in elemental form or in the form ofa chemical compound with the phosphite of formula (I).
 27. A catalystcomprising the phosphite as claimed in claim
 16. 28. A homogeneouscatalyst comprising the phosphite as claimed in claim
 20. 29. Ahydroformylation catalyst comprises the phosphite as claimed in claim16.
 30. A hydroformylation catalyst comprising the phosphite metalcomplex as claimed in claim 20.